Method and device in winding of a web

ABSTRACT

A web is wound onto a core ( 21 ) while supported by winding drums ( 11, 12 ). The web is cut by a cutting device ( 19 ), and a finished web roll ( 10 ) is removed by a transfer device ( 16 ). A new core ( 21 ) is moved to a space between the winding drums ( 11, 12 ), and the winding is stopped to remove the finished roll ( 10 ) and to start a new roll. The core is moved onto support of one winding drum and a support member ( 22 ) and held in place by the support member ( 22 ) until the movable winding drum ( 11, 12 ) has been moved to the starting position of winding.

[0001] The invention relates to a method in winding of a web, in which method the web is wound onto a core while supported by winding drums, in which method the web is cut by a cutting device, a finished web roll is removed by means of a transfer device, a new core is moved to a space between the winding drums, and in which method the winding is stopped to remove the finished roll and to start a new roll.

[0002] The invention also relates to a device in winding of a web, which device comprises winding drums, on support and by means of which the web is wound onto a core into a web roll, which device further comprises a cutting device for cutting the web and a transfer device for removing the finished web roll and a core transfer device for taking a new core to a winding position onto support of a winding drum.

[0003] When forming a roll/rolls in winding of a web in a slitter-winder, in a situation of web set change, it is always necessary to stop the winding before starting a new winding operation and to remove the set and, after a new core has been positioned on the two-drum winder, the winding must be started again. Today, the set change time in winding of a web is in practice about 30 to 70 seconds when mechanized arrangements are used and about 2 minutes when cores are positioned manually. In this description, when referring to a core, one or more cores or other reel spools are meant around which a web, in particular a paper or board web is wound into a web roll/web rolls. By the two-drum winder (two-drum slitter-winder) is meant a winder of the two-drum type in which a web roll is formed on support of winding drums, which winding drums can be drums or sets of belt drums.

[0004] A problem in today's set change technique is the long set change time, which lowers capacity.

[0005] Corresponding prior-art methods and devices have often suffered from the drawback that it has not been possible to control the quality at the start of winding sufficiently well. For example, wrinkles may have been produced at the roll start or bottom because of problems caused by a long cut length in passing the end of the web onto a core, to which the end of the web is attached, for example, with glue or with a double-faced tape.

[0006] With respect to the prior art, reference is made to U.S. Pat. No. 3,841,578, which describes a method and a device for continuously winding material webs into individual rolls. The apparatus used in this prior-art arrangement may comprise a take-up roll, which is placed on the front side of a gap between winding drums, by which an empty reel coming from a reel storage can be pushed through the gap between the winding drums to the winding side of them.

[0007] With respect to the prior art, reference is also made to Finnish patent No. 81 551, which describes a method and a device in winding of a web. In the method, a finished web roll is removed by means of a lowering device. Partly substantially simultaneously with the roll lowering movement a new core is moved into a gap between a first winding drum and a second winding drum. The web is cut and the cut end of the web is attached to the core. In order to remove a finished roll and to start a new winding operation, the winding is slowed down to the set change speed and a rider roll is raised off the finished roll and moved rearwards relative to the finished roll. A set of belt drums is moved in a lateral direction and a new core is moved into a space defined by the first winding drum, the first drum in the set of belt drums, and the finished roll. The set of belt drums is moved back in the lateral direction and the rider roll is moved towards the new core, the rider roll being arranged to push at the same time the finished roll away from the first winding drum. Substantially at the same time, the second drum in the set of belt drums is lowered in a vertical direction, in which connection the finished roll is arranged to be moved to the lowering device. A problem with this prior-art arrangement is that, because of complexity, the structure becomes rather expensive. Moreover, this prior-art arrangement does not actually propose any arrangement for controlled holding of the core when the set of drums is brought into contact with it.

[0008] An object of the invention is to provide an improvement to the winding methods which are known at present such that the drawbacks described above are eliminated or at least minimized.

[0009] An object of the invention is to provide a method and a device in set change enabling a quicker set change than that of the prior-art arrangements.

[0010] An object of the invention is to provide an arrangement for controlled holding of the core when a set of drums is brought into contact with it.

[0011] An object of the invention is to provide a method and a device enabling the quality of winding to be controlled in particular at the beginning of winding.

[0012] The method according to the invention is mainly characterized in that, in the method, the core is moved onto support of one winding drum and a support member and held in place by means of the support member until a movable winding drum/movable winding drums has/have been moved to the starting position of winding.

[0013] The device according to the invention is in turn mainly characterized in that a support member is arranged in connection with the core transfer device to hold the core in place against one winding drum during a set change in winding, that the core transfer device of the device is placed beneath the winding drums, and that at least one winding drum is movable.

[0014] In accordance with an advantageous embodiment of the invention, during set change in winding, a set change arrangement is used in which the rear drum in a winder of the two-drum type moves and a core for starting the next winding operation is fed from between the winding drums from below. At first, the core is supported between the drums against one winding drum, advantageously against the front drum, by means of the support member until the winding drums are in the starting position of winding, after which the support member used for holding the core in place is lowered and the core is in nip contact with both winding drums.

[0015] In accordance with an advantageous feature of the invention, in connection with winding, a cutting method known in itself is used for cutting the web during the slowing down of winding, which is described in the applicant's patent FI 100324.

[0016] In an embodiment in accordance with an advantageous feature of the invention, in which control of the length of the end of the web in cutting is accomplished by means of the machine direction position of a winding drum and/or by means of the position of the end of the web after the web has stopped, the wrinkles caused by too long a web end at the start of winding are eliminated. When the rear winding drum moves during set change in the running direction of the web in a direction away from unwinding, the cut end of the web moves downwards on the surface of the rear winding drum when no more web is unwound from a reeling drum to be unwound. The cutting point of the web, when using the cutting method described in the above-mentioned patent FI 100324, is not at an optimal location for ideal passing of the web around the core, and thus the movement of the winding drum provides a favourable effect in positioning the web end. The movement distance (which is dependent on the position of the rear drum at the start of set change) and the position of the web end after cutting are set by means of control and a suitable combination is selected which gives the best possible position for the web end for passing it around a core. The location of the web end after cutting can be selected from above the nip line between the finished roll and the rear drum. The location of the web end after cutting is adjusted by adjusting the moment of stopping the rotation of the drum. An advantage in the arrangement in accordance with this feature of the invention is also that the reeling drum need not be rotated during set change.

[0017] Thus, the method and the device in accordance with the invention also enable the free end or tail of the web to be positioned accurately.

[0018] In an advantageous application of the method in accordance with the invention, when a new roll is beginning to be finished and the winding is slowed down, the rear drum is moved to a set change position. A cutting blade sets out to perform a cutting function and, for starting a new winding operation, a core is lifted by a core transfer device from between the drums up. The web is held in place on the surface of a winding drum, advantageously on the surface of the rear drum, while the machine is stopped, by means of a web holder and/or by suction produced by means of the winding drum. In the next stage, when the winding has been stopped, the finished roll is moved away by a transfer device by pushing from the winding position, and a core is moved onto support of one winding drum, advantageously the front drum, and of a support member, and the cutting blade is returned to the home position. To start a new winding operation, the rear drum is moved to the starting position and the support member is brought down and the core holders are locked. A rider roll is moved downwards as allowed by the transfer of the finished roll and by the movements of its transfer device. When the rider roll is in its loading position, winding is started.

[0019] With the method/device in accordance with the invention, the set change time can be shorted to about 10 seconds at its shortest, whereby the capacity of the slitter-winder increases by even 10% or more.

[0020] In the following, the invention will be described in greater detail with reference to the figures in the accompanying drawing, to the details of which the invention is, however, not by any means meant to be strictly confined.

[0021] FIGS. 1 to 6 schematically show the method and the device in accordance with the invention in winding of a web.

[0022] In the advantageous exemplifying embodiment of the invention shown in FIGS. 1 to 6, a two-drum winder is formed of a rear winding drum 11 and a front winding drum 12, which may be formed into a set of belt drums comprising drums 14, 15 and an endless belt loop 13 arranged to run around them. A finished roll wound by the winder is designated by the reference numeral 10 and a rider roll by the reference numeral 17 and a transfer device for the finished roll by the reference numeral 16. The reference numeral 19 designates a device for cutting the web. A web holder is denoted with the reference numeral 18 and a core transfer device with the reference numeral 20, and the reference numeral 22 designates a support member for holding a core 21 in place before the winding drums 11, 12 are moved to the winding position after a set change.

[0023] In the situation illustrated in FIG. 1, the roll 10 is being finished. The rider roll 17 presses the finished roll 10 and the transfer device 16 of the finished roll 10 approaches the transfer position in order to move the finished roll 10 away from the winding position. The core 21 has been brought by the core transfer device 20 into a space between the finished roll 10 and the rear winding drum 11 and the set 12 of belt drums. The core 21 is lifted up by the core transfer device 20 from the space between the rear drum 11 and the set 12 of belt drums. During winding, the rear drum 11 has moved to the initial position of set change. During the final slowing down, the web is cut by the cutting device 19 and the tail of the web is held in place against the rear drum 11 by means of the web holder 18.

[0024] In the stage shown in FIG. 2, the transfer device 16 starts pushing the finished roll 10 away from the winding drums 11, 12 and the core 21 is moved onto support of the front drum, i.e. the set 12 of belt drums. The rider roll 17 has been lifted off the finished roll 10. The core transfer device 20 raises the core 21 over the support member 22 to its position and the core 21 is held in place by means of the support member 22.

[0025] In the stage shown in FIG. 3, the finished roll 10 is moved further away by means of the transfer device 16 and the core transfer device 20 moves down towards its home position. The core 21 is held in place against the set 12 of belt drums by means of the support member 22. The rear drum 11 is moved towards the starting position of a new winding operation.

[0026] In the situation shown in FIG. 4, the transfer device 16 returns to its home position, the rider roll 17 starts to move towards the core 21, the rear drum 16 moves towards the starting position of winding, in which connection the distance between the rear drum 11 and the front drum 12 is reduced. The cutting device 19 moves to its home position. The end of the web moves/rolls to an advantageous starting position while the rear drum 11 rolls in the machine direction with respect to the stationary web holder.

[0027] In the situation shown in FIG. 5, the support member 22 of the core 21 starts to move towards its home position and the rear winding drum 11 has moved to the starting position of winding and the tail of the web has reached its position with respect to the core 21 and the rider roll 17 moves towards the core 21.

[0028] In the situation shown in FIG. 6, the rider roll 17 is in nip contact and winding is started.

[0029] Above, the invention has been described with reference to one of its advantageous exemplifying embodiments, but the invention is by no means meant to be narrowly confined to the details of it.

LIST OF REFERENCE NUMERALS

[0030] Roll 10

[0031] Rear winding drum 11

[0032] Front winding drum 12

[0033] Belt of a set (12) of belt drums 13

[0034] Drum of a set (12) of belt drums 14

[0035] Drum of a set (12) of belt drums 15

[0036] Roll transfer device 16

[0037] Rider roll 17

[0038] Web holder 18

[0039] Cutting device 19

[0040] Core transfer device 20

[0041] Core 21

[0042] Support member 22

[0043] Two-drum winder 30 

1. A method in winding of a web, in which method the web is wound onto a core (21) while supported by winding drums (11, 12), in which method the web is cut by a cutting device (19), a finished web roll (10) is removed by means of a transfer device (16), a new core (21) is moved to a space between the winding drums (11, 12), and in which method the winding is stopped to remove the finished roll (10) and to start a new roll, characterized in that, in the method, the core is moved onto support of one winding drum and a support member (22) and held in place by means of the support member (22) until a movable winding drum/movable winding drums (11, 12) has/have been moved to the starting position of winding.
 2. A method as claimed in claim 1, characterized in that, in the method, the web is cut by the cutting device (19) to size and the end of the web is held in connection with a winding drum by means of suction and/or a holder member (18) during set change.
 3. A method as claimed in claim 2, characterized in that the cut length of the web is adjusted by the machine direction position of the winding drum and/or by the position of the web end after the web has stopped.
 4. A method as claimed in claim 1, characterized in that the core is moved onto support of the front winding drum (12).
 5. A method as claimed in claim 1, characterized in that the rear winding drum is moved during set change.
 6. A method as claimed in claim 2, characterized in that the end of the web is held in connection with the rear winding drum (11).
 7. A method as claimed in claim 1, characterized in that, in the method, when a new winding operation is beginning to be finished and the winding is slowed down, the rear winding drum (11) is moved to a set change position and the device (16) for transferring the finished roll away is moved close to the roll (10), that the web is cut by the cutting device (19) and the core (21) is lifted by a core transfer device (20) from between the front winding drum (12) and the rear winding drum (11) upwards and the core (21) is held against the front winding drum (12) by means of the support member (22) and the core transfer device (20) is brought to its home position, and that the finished roll (10) is moved away by the transfer device (16) and, to start a new winding operation, the rear winding drum (11) is moved to a starting position and the core support member (22) is removed and a rider roll (17) is moved down, a web holder (18) is disengaged and a new winding operation is started.
 8. A method as claimed in claim 1, characterized in that, in the method, the web roll (10) that is being formed is loaded by a rider roll (17).
 9. A method as claimed in claim 1, characterized in that, in the method, a new core is moved partly substantially simultaneously with the transfer of the finished roll (10).
 10. A device in winding of a web, which device comprises winding drums (11, 12), on support and by means of which the web is wound onto a core (21) into a web roll (10), which device further comprises a cutting device (19) for cutting the web and a transfer device (16) for removing the finished web roll (10) and a core transfer device (20) for taking a new core (21) to a winding position onto support of a winding drum, characterized in that a support member (22) is arranged in connection with the core transfer device (20) to hold the core in place against one winding drum during a set change in winding, that the core transfer device (20) of the device is placed beneath the winding drums (11, 12), and that at least one winding drum is movable.
 11. A device as claimed in claim 10, characterized in that the device comprises a holder member (18) and/or suction in a winding drum (11, 12) to hold the web at a given location against the winding drum during a set change in winding.
 12. A device as claimed in claim 10, characterized in that the web is arranged to be cut by the cutting device (19) to a cut length such that the position of the movable winding drum in the machine direction and/or the position of the end of the web is/are adjusted after the web has stopped.
 13. A device as claimed in claim 10, characterized in that at least one winding drum of the winding drums (11, 12) of the device is a winding drum formed by a set of belt drums.
 14. A device as claimed in claim 10, characterized in that the device comprises a rider roll (17) for pressing the web roll that is being formed.
 15. A device as claimed in claim 10, characterized in that the movable winding drum is the rear winding drum (11).
 16. A device as claimed in claim 11, characterized in that the holder member (18) is placed in connection with the rear winding drum (11) to hold the end of the web in connection with the rear winding drum (11).
 17. A device as claimed in claim 10, characterized in that the support member (22) is placed such that the core (21) can be held in place against the front winding drum (12). 